Mind Reading Whether we know it or not, we’re all street-corner psychics. Without the ability to divine others’ thoughts and feelings, we couldn’t handle the simplest social situations—or achieve true intimacy with others.

If a baby starts to cry several hours after drinking his last bottle, his mother knows precisely what he’s feeling: He’s hungry. But suppose a woman’s eyes brim with tears while she watches a DVD. Her husband sinks into the couch: What is she so upset about? She might tell him directly: “This movie is so tragic. It’s all about a doomed romance.” That may be true. But she could be thinking about how the story reminds her of her own marital troubles. Maybe she’s feeling hurt because she thinks her husband should realize what’s bothering her and acknowledge it. Or maybe she isn’t even aware that her real-world concerns are intensifying her reaction to the fictional couple.

Quickly and unknowingly, he scours his mental files—on his wife’s relationship history, on her reaction to the fight they had that morning, on the way she typically reacts to similar movies. He notes the particular quiver to her voice, observes the way she’s curled up on the couch, watches the expressions flickering across her face. He takes in information from all of these channels, filters it through his own wishes and biases… until finally it hits him: She knows about his mistress!

Every day, whether we’re pushing for a raise, wrestling with the kids over homework, or judging whether a friend really likes our latest redecorating spree, we’re reading each other’s minds. Drawing on our observations, our databank of memories, our powers of reason, and our wellsprings of emotion, we constantly make educated guesses about what another person is thinking and feeling. Throughout the most heated argument or the most lighthearted chat, we’re intently collecting clues to what’s on the other person’s mind at the moment. “It’s a perceptual ability I call mindsight,” says Daniel Siegel, UCLA psychiatrist and author of The Mindful Brain. “It allows your brain to create a map of another person’s internal state.”

Mind reading of this sort—not to be confused with the infallible superhero kind of telepathy—is a critical human skill. It’s the way we make sense of other people’s behavior and decide on our own next moves. Mind reading enables us to negotiate, compete, cooperate, and achieve emotional closeness with others. It lets us figure out when we’re being manipulated or seduced. It’s how we know when someone finds our jokes hilarious or is humoring us out of politeness. Mind-reading ability is perhaps the most urgent element of social intelligence.

Do it poorly and the consequences are serious: It can lead to conflict born of misunderstanding. It can make us feel lonely within a relationship. It can even incite violence: Abusive husbands typically—and inaccurately—attribute critical thoughts to their wives; that’s why they lash out. Difficulty divining others’ thoughts and feelings—”mindblindness”— characterizes autism and is what makes the condition so socially debilitating.

Decades of research on mind reading (or, as psychologists call it, empathic accuracy) now reveal how it works, who’s especially good at it, and how we can improve our ability to divine others’ thoughts—even when our conversation partners may not know their own minds. The thoughts and feelings of others, including those closest to us, are far from transparent; that makes mind reading the only way to know someone beyond the mere surface. It’s the only way to achieve true intimacy. And the only way to love someone for who he or she really is.